Researchers have identified butyrylcholinesterase (BChE) as the first biochemical marker that could help detect babies at higher risk of dying from Sudden Infant Death Syndrome (SIDS). The death of an apparently healthy infant less than one year old during sleep, SIDS is the one of the leading causes of infant mortality in the U.S. and other parts of the world.
The study was carried out by researchers in Australia at The Children’s Hospital at Westmead in Sydney and the University of Sydney. It was published in The Lancet’s eBioMedicine.
The team analyzed BChE activity in 722 Dried Blood Spots (DBS) taken at birth as part of the Newborn Screening Program, using only samples parents approved for use in de-identified research. BChE was measured in both cases pf SIDS and infants who died from other causes. Results from each subject were compared to those of 10 surviving infants with the same date of birth and gender.
The study found BChE levels were significantly lower in babies who subsequently died of SIDS.
Autonomic dysfunction has previously been implicated in the pathophysiology of SIDS. BChE is an enzyme of the cholinergic system, a major branch of the autonomic system, and its levels may be associated with autonomic function.
The work was led by Carmel Harrington, Honorary Research Fellow at CHW, who lost one of her own children to SIDS 29 years ago. She says the results could be game changing.
“Babies have a very powerful mechanism to let us know when they are not happy. Usually, if a baby is confronted with a life-threatening situation, such as difficulty breathing during sleep because they are on their tummies, they will arouse and cry out. What this research shows is that some babies don’t have this same robust arousal response,” Harrington said.
She adds that, “This has long been thought to be the case, but up to now we didn’t know what was causing the lack of arousal. Now that we know that BChE is involved we can begin to change the outcome for these babies and make SIDS a thing of the past.”
The incidence of SIDS has been more than halved in recent years due to public health campaigns addressing the known major risk factors of prone sleeping, maternal smoking, and overheating. However, SIDS remains a major contributor to infant deaths.
After losing her son, Damien, to SIDS, Harrington dedicated her career to research on the condition, supporting much of her work through her crowd-funding campaign, Damien’s Legacy. She says these results not only offer hope for the future, but answers for the past.
“An apparently healthy baby going to sleep and not waking up is every parent’s nightmare and until now there was absolutely no way of knowing which infant would succumb. But that’s not the case anymore,” she said.
“This discovery has opened up the possibility for intervention and finally gives answers to parents who have lost their children so tragically. These families can now live with the knowledge that this was not their fault.”
The next steps for researchers is to begin looking at introducing the BChE biomarker into newborn screening and develop specific interventions to address the enzyme deficiency. It is expected this will take around five years to complete.
“This discovery changes the narrative around SIDS and is the start of a very exciting journey ahead. We are going to be able to work with babies while they are living and make sure they keep living,” Harrington added.
